Possible physical risk factors (PRFs) for computer-related musculoskeletal disorders include forces applied to the input devices (the keyboard and mouse), upper extremity postures, and patterns of work and rest activities. The exposure assessment literature related to computer work lacks quantitative data on PRFs in the actual workplace. Studies designed to measure objectively the exposure to these PRFs with instruments such as force sensors and electrogoniometers have been limited to the laboratory setting, mainly due to the lack of equipment development suitable for field studies. While other exposure assessment methods exist, few objectively measure exposure of the musculoskeletal system to multiple PRFs at the computer workstation in the field. A new field-based exposure assessment monitoring system, that measures keyboard and mouse usage, typing and mouse force, wrist postures, and computer work-rest cycles, will be developed. The proposed project will validate the force sensing technologies, the other sensor equipment and the measurement techniques, first in a controlled laboratory study and then in a field study. The overall objective is to investigate how best to measure and characterize physical exposures in order to gain a better understanding of PRFs in the office workplace. In addition, epidemiologic studies have indicated that chronic musculoskeletal disorders of the upper extremity are more prevalent among women than among men. There are many possible explanations for the difference between genders, including differences between the exposure to PRFs. The new exposure assessment system will be tested in a field setting of 60 computer operators (30 men, 30 women) to quantify exposures and determine whether there are differences in exposures to PRFs between genders. The outcomes of this study include a portable, accurate, reliable exposure assessment system for collecting force and usage data in field settings as well as descriptive data of physical exposure differences between men and women.